------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset: TSIS-1 SIM V13 Solar Spectral Irradiance 2. Authors: Penton, Steven V., Chambliss, M., Richard, E., Béland, S., Charbonneau, L., Coddington, O., Kessler, C., Maclay, M., McMaster, L. Peck, C. 3. Contact information: steven.penton@lasp.colorado.edu 4. Date of data collection: 2018-03-14 to 2025-09-16 -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC-BY-4.0 https://creativecommons.org/licenses/by/4.0/ 2. Links to publications that cite or use the data: "SORCE and TSIS-1 SIM Comparison: Absolute Irradiance Scale Reconciliation" [Paper #2021EA002122R] in Earth and Space Science, in production. DOI: 10.1029/2021EA002122 3. Recommended citation for the data: Penton, Steven V., Chambliss, M., Richard, E., Béland, S., Charbonneau, L., Coddington, O., Kessler, C., Maclay, M., McMaster, L. Peck, C., (2025). TSIS-1 SIM V13 Solar Spectral Irradiance [Data set]. University of Colorado Boulder, https://doi.org/10.25810/TBD. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List: A. Filename: TSIS_SIM_V13.1_Release_Notes.pdf B. Filename: tsis_ssi_L3_c12h_v13_20180314_20250916.nc C. Filename: tsis_ssi_L3_c12h_v13_20180314_20250916.sav D. Filename: tsis_ssi_L3_c12h_v13_20180314_20250916.txt.gz E. Filename: tsis_ssi_L3_c24h_v13_20180314_20250916.nc F. Filename: tsis_ssi_L3_c24h_v13_20180314_20250916.sav G. Filename: tsis_ssi_L3_c24h_v13_20180314_20250916.txt.gz 2. Relationship between files: A. tsis_ssi_L3_c12h_v13_20180314_20250916: Contains spectral solar irradiance (SSI) measurements with a 12-hour cadence. B: tsis_ssi_L3_c24h_v13_20180314_20250916: Contains spectral solar irradiance (SSI) measurements with a 24-hour cadence. C. TSIS_SIM_V13.1_Release_Notes.pdf: Contains details of V13 release notes. 3. Software-specific information: (Name, version, and operating system for software needed to open each file type.) A. .nc: netCDF files comply with the standard machine independent NetCDF 4 library, and compatible with HDF5. Refer to Unidata for NetCDF details https://docs.unidata.ucar.edu/netcdf-c/current/credits.html B. .sav: IDL SAVfile files can be opened with any version > 8.3 of the Interactive Data Language (IDL) available from NV5 Geospatial at https://www.nv5geospatialsoftware.com/Products/IDL C. .gz: gzip files are compressed with the standard gzip library (https://www.gnu.org/software/gzip/) and contain the data in a large text file. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods for data collection or creation: The TSIS-1 SIM measures SSI (units of W m-2 nm-1) incident on a plane surface at the top of the atmosphere that is normal to the Sun two times per day from 200 to 2400 nm at variable (~2-45 nm) spectral resolution. The integrated irradiance contribution measured by SIM is approximately 96% of the total solar irradiance measured by the TIM instrument. The SIM is a follow-on to the SORCE SIM instrument with improvements in instrument design, relative accuracy (0.2% over the full spectrum), long-term stability (to better than 0.05% per year), and relative precision (0.01%). These improvements are key to understanding the contributions from varying spectral irradiance on climate. Long-term relative accuracy is maintained by duty cycling three independent spectrometers and directly measuring the prism transmission for each. ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c12h_v13_20180314_20250916.txt ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 9602656 3. Variable List: A. Name: nominal_date_yyyymmdd, R8, f11.2 Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, R8, f11.2 Description: Julian Date of measurement. 12-hour data are on 0.25 or 0.75 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, R4, f9.3 (nm) Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, I2, i3 Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, I2, i3 Description: Version of data release. F. Name: irradiance_1AU, R8, e15.8 (W/m^2/nm) Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UI2, i6 Description: Level 3 data quality flag (DQF) that contains nonexclusive bit flag values. 0: good data 1: missing data, irradiance values with a missing data flag are given as 0.0 2: data that has been backfilled from the previous day. 32: data taken after September 4, 2023 (the date of the DSP-anomaly), that has received a wavelength and ESR pairing-dependent spectral correction (ESR_ANOMALY_CORRECTED) 512: data taken during the HFSS-B(OFF) pointing anomaly period of 19 March 2022 to 19 May 2022 (HFSSB_CORRRECTED_POINTING). Multiple bits can be set simultaneously. For example, DQF = 514 indicates back-filled data, where the data was taken during the HFSS-B(BAD) pointing anomaly; this data is valid, but not nominal. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c24h_v13_20180314_20250916.txt ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 5064328 3. Variable List: A. Name: nominal_date_yyyymmdd, R8, f11.2 Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, R8, f11.2 Description: Julian Date of measurement. 24-hour data are on 0.5 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, R4, f9.3 (nm) Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, I2, i3 Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, I2, i3 Description: Version of data release. F. Name: irradiance_1AU, R8, e15.8 (W/m^2/nm) Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability, R8, e15.8 (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UI2, i6 Description: Level 3 data quality flag is the same as reported in the 12-hour text file. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c12h_v13_20180314_20250916.sav ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 9602656 3. Variable List: Data is stored in an IDL structure named "DATA". Description in the string array "DOC_SIM". A. Name: nominal_date_yyyymmdd, DOUBLE Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, DOUBLE Description: Julian Date of measurement. 12-hour data are on 0.25 or 0.75 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, FLOAT Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, INT Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, INT Description: Version of data release. F. Name: irradiance_1AU, DOUBLE Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, DOUBLE (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability,DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UINT Description: Level 3 data quality flag is the same as reported in the 12-hour text file. 4. Data codes (e.g., N/A = Not applicable): ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: tsis_ssi_L3_c24h_v13_20180314_20250916.sav ----------------------------------------- 1. Number of variables: 10 2. Number of cases/rows: 5064328 3. Variable List: Data is stored in an IDL structure named "DATA". Description in the string array "DOC_SIM". A. Name: nominal_date_yyyymmdd, DOUBLE Description: Calendar Date of measurement in human readable format (e.g., 20210320.46). B. Name: nominal_date_jdn, DOUBLE Description: Julian Date of measurement. 24-hour data are on 0.5 day centers. Scan start time determines which temporal bin is populated. C. Name: wavelength, FLOAT Description: Wavelength at center of measurement bin. D. Name: instrument_mode_id, INT Description: TSIS-1 SIM detector identifier (86 (UV), 85 (VIS), 84 (IR), 83 (ESR)). E. Name: data_version, INT Description: Version of data release. F. Name: irradiance_1AU, DOUBLE Description: Solar Spectral Irradiance corrected to a distance of 1AU. G. Name: instrument_uncertainty, DOUBLE (W/m^2/nm, 1 sigma) Description: Instrument Uncertainty (in Watts/m2/nm) is a pre-launch measure of instrument uncertainty with contributions from component and unit-level instrument laboratory characterizations and calibrations with the final end-to-end full spectrum validation of the measured irradiances against a NIST-traceable cryogenic radiometer performed in LASP’s Spectral Radiometer Facility. Reported uncertainties for Version 1 represent an upper limit to the calibration accuracy for each spectral band pending the resolution of an additional correction in the polarization dependence of the entrance slit transmission discovered after SIM launch. H. Name: measurement_precision, DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Precision (in Watts/m2/nm) is derived from a measure of the on-orbit variance in the scan-to-scan repeatability in the observed spectral irradiances. This value is an upper limit of measurement precision. I. Name: measurement_stability,DOUBLE (W/m^2/nm, 1 sigma) Description: Measurement Stability (in Watts/m2/nm) is a relative metric of the overall on-orbit degradation correction uncertainty. It has contributions from uncertainty due to post-processing of data (including correction of instrument degradation), and uncertainty due to differences between observed irradiances for the 3 separate SIM channels. The precision of the three instrument channels is added to the reported stability as a residual sum of squares. Measurement stability is given as 0.0 at wavelengths > 1050 nm, where we do not currently calculate a degradation correction, and for all data that arrives after the bi-annual Channel C calibration scans. The bi-annual Channel C scans trigger a new data release version, so there could be up to six months of measurement stability values that are 0.0 until they are determined during the creation of the next data release. J. Name: quality, UINT Description: Level 3 data quality flag is the same as reported in the 12-hour text file. 4. Data codes (e.g., N/A = Not applicable):